The present invention relates to a grain wagon or grain cart having a unloading auger conveyor and of the type disclosed in U.S. Pat. Nos. 5,340,265, 6,296,435, 6,497,546, 7,134,830 and 8,047,757 which issued to the assignee of the present invention and the disclosures of which are herein incorporated by reference. The grain carts are usually pulled by a tow tractor for transporting grain from a harvesting combine in a field to an open top semi-trailer which transports the grain over the road to a grain elevator for drying and storage. The grain cart has a power driven single auger grain unloading conveyor which includes an inclined lower auger conveyor section extending adjacent an inclined front left corner portion of the grain cart container. An upper auger conveyor section extends from the lower section and projects upwardly, laterally outwardly and forwardly from the container in a grain discharge position so that the discharging of the grain can be conveniently viewed by the driver of the tow tractor. The upper auger conveyor section is pivoted by a fluid cylinder between the discharge position and a stored position adjacent the front wall of the container, as shown in the above-mentioned patents. The front folding upper auger conveyor section also enables the driver of the tow tractor to view all movements of the upper conveyor section between its stored position and its grain discharge position.
Grain carts having an inclined folding unloading auger as disclosed in the above-mentioned patents have been produced by the assignee of the patents, and similar grain carts with a folding unloading auger have been produced by other companies for over 20 years. When the grain is unloaded and discharged into an open top rectangular semi-trailer for delivery to a grain elevator, the grain is discharged from the auger conveyor through a discharge spout which has its axis in the plane of the auger axis. As a result, the grain does not completely fill opposite corner portions of the open top rectangular semi-trailer unless a person climbs into the trailer or onto a wall of the trailer and manually pulls or moves the grain into the opposite corner portions of the trailer with a shovel or other tool. If the grain is not manually moved to fill up the opposite corner portions, the opposite corner portions of the trailer are not topped off with grain as is the rest of the semi-trailer, and the grain is transferred to the grain elevator without the entire semi-trailer filled and topped off with grain including the opposite corner portions. One attempt to fill more of the opposite corner portions of a rectangular semi-trailer with grain being discharged from the unloading auger was to mount the discharge spout on the conveyor housing so that the spout may be oscillated back and forth on the axis of the conveyor auger. However, the rotatable discharge spout still does not completely fill opposite corner portions of the semi-trailer.